iStock/Thinkstock(MUNCIE, Indiana) — An Indiana family that decided against vaccinating a 3-year-old is now haunted by that decision, wondering if a flu shot could have saved the girl’s life.

Alivia Viellieux, of Muncie, Indiana, died at home Monday morning, just days after being diagnosed. The girl’s grandmother, Tameka Stettler, said the family is second-guessing its decision not to vaccinate her.

Stettler said Alivia’s parents declined to give her the flu shot after hearing that the vaccination could be ineffective.

“Alivia did not have it because they had told us once the flu is going around it’s not going to matter if you got it or not,” Stettler said in an interview with ABC affiliate WRTV on Monday. “We just decided not to put those chemicals and the girls body if it’s not gonna help.”

“Nothing anybody says or does is going to bring that little girl back to us,” she added.

Stettler said the family was preparing to celebrate Alivia’s fourth birthday next month and that the girl already was signed up to attend preschool later this year.

Alivia had a blazing temperature of 106 degrees when the family took her to a local medical clinic last Tuesday, Stettler said.

The clinic said she tested positive for Influenza A and sent her to the emergency room at Ball Memorial Hospital, where she stayed for three days.

The hospital sent her home on Thursday after she appeared to be doing better, but the progress didn’t last. Alivia died in her sleep on Monday morning.

“She was eating cheerios last night,” Stettler said. “She was walking last night. How does that just happen?”

The exact cause of Alivia’s death has not been determined. Representatives at Ball Memorial Hospital, where she was last treated, declined to comment on the specifics of her case but issued a statement that read: “While we can’t discuss any patient’s care, we are very saddened by her passing. Our hearts go out to her family.”

Her death comes as the nation battles one of the most brutal flu outbreaks on record. The U.S. Centers for Disease Control and Prevention said at least 14,676 people have been hospitalized with influenza since the flu season began in October — double the number from all of last year and the highest ever recorded.

At least 63 children have died from influenza in the current flu season, according to the CDC, which is urging those who haven’t been vaccinated to do so.